gcc12 seems to be not reproducible and one of the difference is visible in the
libgccjit package which, for libgccjit.so itself is visible in different sized
.text and .rodata:

   [16] .text             PROGBITS         00000000002b97a0  002b97a0
-       0000000001105e42  0000000000000000  AX       0     0     16
-  [17] .fini             PROGBITS         00000000013bf5e4  013bf5e4
+       0000000001105c82  0000000000000000  AX       0     0     16
+  [17] .fini             PROGBITS         00000000013bf424  013bf424
        000000000000000d  0000000000000000  AX       0     0     4
   [18] .rodata           PROGBITS         00000000013c0000  013c0000
-       000000000042d950  0000000000000000   A       0     0     32
-  [19] .stapsdt.base     PROGBITS         00000000017ed950  017ed950
+       000000000042d8f0  0000000000000000   A       0     0     32

disassembly starts with a huge blob of

Disassembly of section .text:

00000000002b97a0 <gcc_jit_compatible_types@@LIBGCCJIT_ABI_20-0x1098dc0>:
...
0000000001352560 <gcc_jit_compatible_types@@LIBGCCJIT_ABI_20>:
 1352560:       f3 0f 1e fa             endbr64

which isn't very useful unfortunately.

Similar can be observed with cc1obj:

   [17] .text             PROGBITS         0000000000624690  00224690
-       00000000012796dc  0000000000000000  AX       0     0     16
-  [18] .fini             PROGBITS         000000000189dd6c  0149dd6c
+       00000000012796cc  0000000000000000  AX       0     0     16

the disassembly isn't too usable either, it starts within a blob with
local functions as well.

Since this is all -fprofile-use (but with -fprofile-reproducible=parallel-runs)
and with -flto debugging this is hard.